The use of an ion beam column for repairing semiconductor masks is known from the prior art. The ion beam column has an ion source, which provides a plurality of ions of different suitable elements, which have different ion masses. The ions are combined in an ion beam and directed toward a semiconductor mask to be repaired. A desired type of ions is selected on the basis of their mass and their charge with the help of a filter which provides both an electric field and a magnetic field. Ultimately only these selected ions are focused onto the semiconductor mask as an ion beam. Due to an interaction of the ion beam incident on the semiconductor mask with the material of the semiconductor mask, interaction particles are generated, in particular secondary electrons or secondary ions, which are emitted from the semiconductor mask. A detector detects the interaction particles. Reference is made to U.S. Pat. No. 5,035,787 and WO 88/09049 regarding the above prior art, which are incorporated herein by reference.
As mentioned previously, the known method relates to the repair of semiconductor masks only, however, not to an analysis of an organic sample, for example, of a cell structure.
The method of matrix assisted laser desorption/ionization, known by its abbreviation MALDI, is used, in particular for analyzing an organic sample. This is a method for ionizing molecules. MALDI is based on co-crystallization of a matrix to be examined with an analyte. Excitation with the aid of laser pulses causes fragments on the surface of a crystal to detach. These fragments are examined using mass spectrometry. The mass spectra generated thereby are compared with other mass spectra which are stored in a database. Each mass spectrum of the other mass spectra reproduces properties of a well-defined material or substance, so that by comparing the generated mass spectra with the stored other mass spectra, conclusions may be drawn about the material or materials of the examined organic sample. However, MALDI provides a spatial resolution of usually only 0.1 mm, at best of 25 μm. This resolution is insufficient for many applications.
However, secondary ion mass spectrometry, also known by its abbreviation SIMS, is known as a high spatial resolution method. In this method, the surface of a sample to be examined is irradiated with a focused primary ion beam. The secondary ions obtained here, emitted by the surface of the sample, are detected and examined using mass spectrometry. The secondary ions are selected and identified on the basis of their ion mass, so that conclusions may be drawn about the sample. However, SIMS is barely or not at all used in analyzing organic substances in conjunction with a highly energy-rich primary ion beam incident on the organic substance. The reason therefor is that the primary ion beam often destroys the organic molecules of the organic substance in such a way that the organic molecules may no longer by distinguished by SIMS.
Accordingly, it would be desirable to provide a device and method for analyzing an organic sample that provides high spatial resolution.